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How
Much Nitrogen Can you Afford?
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In
typical Wyoming hay meadows, production will respond dramatically to the
application
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of
Nitrogen fertilizer. As with most
production functions, the law of diminishing returns
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governs
the economic decision-making process.
The production functions upon which the
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calculations
this spreadsheet uses are derived from specific research trials. The actual
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response
of different fields will vary, depending upon water, soils, climate,
management, etc.
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This
spreadsheet, therefore, must only be used as a guide in helping a rancher
make decisions.
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Instructions: Input the cost of fertilizer, its
percentage of nitrogen, your hay's market value, and
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your
added cost to harvest additional production.
Upon setting these variables, the output tables
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may
be as an aid in fertilizer application decisions. Input cells are shaded. All other
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cells
are protected.
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Scroll
Down to see input numbers and see results
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INPUT
SECTION
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Cost of
Fertilizer ($/ton)
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Formulation
percentage (i.e. 33%, 24%, ??)
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%
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Market
Value of Forage ($/ton)
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Cost per
ton to harvest the additional production
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/ton
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OUTPUT SECTION
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lbs
of Available Nitrogen
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Cost per
pound of available Nitrogen
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cents/lb.
Available Nitrogen
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Marginal
value of added pound of hay
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cents/lb
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Number of Lbs. of Hay the last Lb. N must produce
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with a
net value of
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Predicted Yield Change in pounds for the LAST Pound of N
applied
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(If the added value of the hay is greater than the value
of fertilizer input, it makes sense to use that rate)
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Cells
with values less than
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are uneconomical
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(production function)
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Y=33.42-0.1652N
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Y=31.54-0.1388N
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Y=24.88-0.1498N
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Fertilizer Applicaton
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Native
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Improved
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Grass-Alfalfa
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20
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40
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60
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80
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100
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120
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140
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160
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based upon J.J. Jacobs, et.al, "Fertilizing Wyoming
Hay Meadows:
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How Much Nitrogen Can You Afford?",
B-828R, April 1993.
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Value
of production for the last Pound of N
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Cells
with values less than
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are uneconomical
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Fertilizer Applicaton
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Native
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Improved
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Grass-Alfalfa
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20
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40
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60
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80
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100
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120
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140
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160
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Spreadsheet
Programming by Eric Peterson, Bridger Feuz |
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